Heparin column analysis of serum type 5 tartrate-resistant acid phosphatase isoforms

The objective of the present study was to develop a specific method for the separation of tartrate-resistant acid phosphatase (TRAP) derived exclusively from osteoclasts. Heparin column-bound TRAP in human serum was separated into three peaks of TRAP activity when eluted with a linear gradient of sodium chloride. The last peak corresponded to TRAP 5b which was first named according to its electrophoretic mobility [Clin. Chem. 24 (1978) 309] and was considered to be derived from osteoclasts [J. Bone Miner. Res. 13 (1998) 683]. The second peak was found to be TRAP 5a. The height of the last peak varied from age to age.